Grant-in-Aid for Developmental Scientific Research (B)
|Allocation Type||Single-year Grants|
|Research Institution||Kyoto Institute of Technology|
KANAMORI Hitoshi Kyoto Inst.Tech., Electronic & Information Science, professor, 工芸学部, 教授 (70027770)
SATO Toshiyuki Shimadzu Co., chief research staff, 中央研究所, 主任
TAKIGAWA Atsushi Hiroshima Pref.College of Health and Welfare, associate professor, 助教授 (80197227)
MATSUMOTO Masao Osaka Univ., Faculty of Medicine, associate professor, 医学部, 助教授 (50149944)
NAKAMORI Nobuyuki Kyoto Inst.Tech., Electronic & Information Science, associate professor, 工芸学部, 助教授 (20107353)
YAMADA Masayoshi Kyoto Inst.Tech., Electronic & Information Science, professor, 工芸学部, 教授 (70029320)
|Project Period (FY)
1993 – 1995
Completed(Fiscal Year 1995)
|Budget Amount *help
¥4,900,000 (Direct Cost : ¥4,900,000)
Fiscal Year 1995 : ¥900,000 (Direct Cost : ¥900,000)
Fiscal Year 1994 : ¥1,000,000 (Direct Cost : ¥1,000,000)
Fiscal Year 1993 : ¥3,000,000 (Direct Cost : ¥3,000,000)
|Keywords||x-ray imaging / patient dose / semiconductor array|
(1)Selection of the dopant of CdTe detector
We found that the detector made using Cl-doped crystal was most adequate for the diagnostic imaging device by comparisons of the dopants of In and Ga by the reason of good photon counting response.
(2)Clinical application of a CdTe detector array
Digital breast image were made by using a multichannel Cl-doped detector array having 768*4 pixels with 500 mum intervals. Clinical image quality of lung and heart was better than the quality of conventional x-ray images.
(3)Measurement of scattered x-ray spectra impinged into the the pixel of an image plane
By using a conical collimator of 45ﾟ angle and a beam stopper, we separated the x-ray spectra into primary and scattered components at a given point of the image plane. When an anti-scatter grid was applied to this measurement, we also could separate the spectra.
(4)Calculation of scattered x-ray spectra impinged into the the pixel of an image plane
Bucky factors and contrast improvement factors were obtained by the results of the scattered x-ray spectra calculated by the Monte Carlo method under the presence of a grid.
(5)Relation between scatter fraction, image contrast and dose
We proposed the contrast-dose diagram which indicated the relation between image contrast and dose for various scatter fractions. By using this diagram we can find the optimum scatter fraction for minimum dose. This method was applied in the clinical radiograph of Sella Turcica in a head phantom.
(6)Analysis of the radiographic mottle
Radiographic mottle, one of the important factor for the x-ray image quality, diminishes the delectability of low-contrast objects. We obtained and explained the tube voltage dependence for the mottle of low and high speed screen/film systems.